Tray for receiving foodstuffs and a process and apparatus for producing it

ABSTRACT

The tray for packs of especially liquid-secreting foodstuffs (for example, meat) is produced from a three-layer sheet, the two outer layers (11, 12) of which consist of foamed polystyrene, while a middle enclosed sheet consists of a narrower strip-shaped insert (13) made of absorbent material (for example, fibrous paper material). In the regions left uncovered by the narrower insert (13), the outer layers (11, 12) are connected directly to one another by means of gluing, welding, etc. The upper layer (11) pointing towards the packaged article has holes (14) which are continuous to the insert (13) and through which liquid (for example, meat juice) flows off and is then stored in the absorbent insert (13).

The invention relates to a tray for receiving foodstuffs, especiallythose secreting liquids, such as, for example, meat, fish, poultry, etc.The invention also relates to a process for producing a tray, and to anapparatus for producing trays.

In general, the problem arising in the packaging of foodstuffs, whichsecrete liquids, especially meat, etc., is that, on the one hand, thepacks should be as air-tight and liquid-tight as possible, and, on theother hand, the liquids, such as, for example, blood, meat juice, etc.,escaping from the foodstuff during transport and storage should not flowfreely inside the pack, since this is considered disagreeable by theconsumer and, when the pack is opened or is even damaged during storageand transport, makes the liquids run out and thus causes soiling.

Trays of this type have previously been made of cardboard which isabsorbent to a certain extent and consequently absorbs the liquids.However, such cardboard trays become soft in time and consequently losetheir leak-proofing property, so that bacteria can also arise. To anincreasing extent, therefore, trays of this type are nowadays made offoamed liquid-tight plastic, for example polystyrene.

In plastic trays of this type, to absorb liquids it is known to place alayer of absorbent material, especially paper, on the floor (topside) ofthe tray. A multi-layer paper blank, liquid-tight on its topside, hasbeen used for this purpose. It is known to use parchment for thisuppermost layer. Several absorbent layers are arranged under it. Theliquid or meat juice can therefore enter the region of the absorbentlayers and be absorbed from the sides only. Since this insert isdeformed as a result of the absorption of liquid, however, troughs fromwhich the liquid cannot flow off form there. Also, this paper insert hasan unattractive appearance, so that the consumer is give the impressionthat the pack in unhygienic. Moreover, the outlay in production termsinvolved in providing these paper blanks is relatively high, inparticular that involved in attaching them to the floor of the tray bymeans of adhesive.

The object of the invention is, therefore, to provide a tray of the typementioned in the introduction, which is liquid-tight, absorbent to agreat extent and simple to produce, as well as a process and anapparatus for producing it.

Accordingly, in the invention, the absorbent material is .[.embedded.]..Iadd.disposed .Iaddend.in the tray itself. On the inside, the tray isprovided, in the region of this absorbent material, with orifices whichpass through the originally leak-proof outer skin of the tray, thusmaking a connection with the inner absorbent layer. Thus, the liquidfrom the packaged article passes through the orifices into the absorbentlayer and is absorbed here with a high capacity. No liquid remains inthe tray. Also, there are no relatively large stains or residues ofliquid, such as, for example, blood or meat juice, on the inside of thetray.

According to the invention, the absorbent insert is made strip-shaped,its width being such that the insert does not extend into the regions ofthe raised side walls of the tray. Thus, in the longitudinal directionof the tray, the insert is limited to the region of the floor surface,and it covers at least the regions of the orifices in the inner tray.

In the longitudinal direction of the tray, the nonabsorbent insert alsoextends in the regions of the raised transverse side walls, that is tosay from edge to edge.

The trays according to the above invention can be produced continuously.Two sheets of plastic, especially foam material, preferably extrudedpolystyrene or expanded polystryrene, are each drawn off directly froman extruder or from a reel and brought together, at the same timereceiving a middle sheet of absorbent material, especially paper.Because the width of the sheet of absorbent material is small, the traysare connected together in the regios of the raised side walls directlyadjacent to one another, specifically either by gluing or by sealing orwelding. In the first-mentioned case, an adhesive is coated on, forexample via a sheet dye, specifically on the lateral region of theplastic sheet not covered by the absorbent insert. After the sealing orwelding operation, the side walls of the tray which are left free of thenon-absorbent insert can be connected together either as a result of theheating of the surfaces to be joined to one another by means ofconventional radiant heaters or else by means of heated transport ordeflection rollers.

The orifices in the (inner) layer of the tray are appropriately designedas continuous stamped-out portions which, where rectangular or squaretrays are concerned, are arranged in parallel, especially lateral rows,specifically over the entire length, that is to say also in the regionof the raised transverse side walls. The holes are preferably stampedout before the three sheets are brought together, specificallypreferably as a result of the perforation of the (upper) plastic sheet.

In this stamping operation, it is possible to ensure, for example as aresult of the additional effect of heat, that the regions surroundingthe holes are made funnel-shaped so that the drainage effect isimproved.

An examplary embodiment of the invention is explained below withreference to the drawings. In the drawings:

FIG. 1 shows a plan view of a tray;

FIG. 2 shows an enlarged longitudinal section II--II through the tray inthe region of several orifices;

FIG. 3 shows an enlarged cross-section III--III through the tray in theregion of one orifice;

FIG. 4 shows a further-enlarged cut-out IV taken from the illustrationin FIG. 3;

FIG. 5 shows a diagrammatic view of an apparatus for producing the tray;

FIG. 6 shows a view of the nip at the connection station in FIG. 5;

FIG. 7 shows a view similar to that of FIG. 6, but with severalabsorbent inserts lying next to one another.

FIGS. 1 to 4 show a rectangular tray 10. This consists of three layers,in particular an upper layer 11, a lower layer 11 and an intermediateabsorbent insert 13. The two layers 11 and 12 preferably consist offoamed plastic, for example polystyrene. The absorbent insert 13consists especially of paper, such as, for example, absorbent fibrousmaterial. Edges projecting upwards are formed in lateral regions of thetray 10, in particular side edges 15 extending in the longitudinaldirection of the tray 10 and transverse side edges 16 extending in thetransverse direction.

In the bottom wall 44 of the tray 10, the upper layer 11 has a pluralityof orifices 14 which extend through to the absorbent insert 13. In thepresent exemplary embodiment, these orifices 14 are distributeduniformly over the upper layer 11, specifically in two parallel rowsextending in lateral regions along the tray 10. Each row has orifices 14arranged in succession at approximately the same distance from oneanother, the rows having orifices 14 not only in the bottom wall 44 ofthe tray 10, but also in the transverse side walls 16. As can be seenparticularly in FIG. 4, the orifices 14 are designed as continuouscylindrical holes. Towards the inside of the tray 10, the orifices 14are made funnel-shaped. For this purpose, the upper edges of theorifices 14 are rounded off in a continuous radius which starts from thesurface of the upper layer 11 directed towards the inside of the tray 10and ends in the orifices 14. FIGS. 1 and 2 also show that the orifices14 extending in the region of the transverse side walls 16 are slightlyoval as a result of the erection of the transverse side walls 16 duringthe deep-drawing of the tray 10.

FIGS. 1 and 3 show that the absorbent insert 13 extends in a directiontransverse relative to the tray 10 only over the bottom wall 44 of thelatter. Because of this, the side walls projecting upwards consist onlyof two layers, in particular the layers 11 and 12, which rest directlyon one another there and are connected together, for example by means ofgluing, hot-sealing and/or welding. The width of the strip-shaped insert13 can be reduced in comparison with the illustration in FIG. 3 at mostso that the insert 13 still covers all the orfices 14.

As shown in FIG. 2, as regards its length, the strip-shaped insert 13extends over the entire length of the tray 10. As a result, thetransverse side walls 16 are also made three-layered.

FIG. 5 illustrates diagrammatically an apparatus for producing thethree-layer tray 10 according to the invention. Two plastic sheets 28and 29 for the upper layer 11 and the lower layer 12 and a sheet 30 ofabsorbent material for the absorbent insert 13 are wound on three reels25, 26 and 27. The upper sheet 28 for the upper layer 11 is guided viadeflecting rollers 31 and 32 to a stamping station 40 where the orifices14 are stamped in the upper layer 11. In this exemplary embodiment, thestamping station 40 consists of a stamping roller 41 provided withappropriate spikes and of an opposing counterroller 42, between whichthe upper sheet 28 is guided through for stamping. Subsequently, theupper sheet 28 now provided with orifices 14 is further deflected at adeflecting roller 33. From here, the upper sheet 28 is guided to a pairof press rollers 34 and 35, where the upper sheet 28 is combined withthe middle sheet 30 unwound from a reel 27 and with the lower sheet 29which comes from a reel 26 and which has previously been deflected viatwo deflecting rollers 36 and 37. It can be seen from FIG. 6 that thenarrower middle sheet 30 is guided centrally between the wider topsheets 28 and 29, so that there will remain on both sides of the middlesheet 30 edge regions which have no intermediate layer and which servefor the subsequent formation of the side walls 15.

In the nip between the press rollers 34 and 35, adhesive is coated on tothe sheets 28 and 29 by a device (not shown), specifically preferablyonly in edge regions not covered by the middle sheet. As a result, thethree-layer material thus formed is glued only where the upper sheet 28and lower sheet 29 for the upper layer 11 and the lower layer 12 aredirectly together.

Instead of gluing with an adhesive, the sheets 28 and 29 can also behot-sealed to one another, pressure being exerted at the same time bymeans of the press rollers 34 and 35 which in this case are heated. Thepress rollers 34 and 35 can, if appropriate, be heated in such a waythat a particularly intensive heat effect occurs at the points where theupper sheet 28 and the lower sheet 29 rest directly on one another. Evenwhen adhesive is used, the press rollers 34 and 35 can be heated tocause the adhesive to harden more quickly. Alternatively, the regions ofthe sheets 28, 29 to be glued together can also be activated thermallyby means of radiant heaters.

After the sheet material for the tray 10 has been connected together,the layered sheet 24 formed between the press rollers 34 and 35 isdeflected at a further deflecting roller 39. From here, the layeredsheet 24 is finally fed to a deep-drawing station 43 indicateddiagrammatically in FIG. 5, in which the tray 10 is shaped from thelayered sheet 24. At the same time, the finished tray 10 is also trimmedin the deep-drawing station 43, as a result of which the finished trays10 are severed from the layered sheet 24, because the deep-drawingstation 43 contains a trimming tool consisting of a collar projecting onthe female mould and a corresponding recess in the male mould. It isalso possible to heat the deep-drawing station 43 to connect the sheets28 and 29 together, so that welding or the like of the layered sheet 24only takes place when the deep-drawing station 43 is reached, instead ofbetween the press rollers 34, 35 which in this case can be omitted.

Finally, it is also possible to feed the upper sheet 28 and lower sheet29 to the apparatus illustrated in FIG. 5 by discharging them directlyfrom two extruders and treating them further, at the same timedeflecting them in an appropriate way. One extruder may also besufficient to produce the sheets 28, 29, in particular if this extruderproduces a sheet of double width which is severed to form the two sheets28 and 29 and deflected in an appropriate why. In such a case, there isno longer any need for the reels 25 and 26.

FIG. 7 shows how several individual sheets for the trays 10 can beproduced on one wider sheet. Here, three middle sheets 30 are laid oncontinuous sheets 28 and 29, specifically each at a distance from oneanother. These distances again form the lateral regions 16, in which thesheet 29 is then connected to the sheet 28. For further processing, thesheets can then be severed longitudinally (the broken lines in FIG. 7)or supplied to several (here three) parallel deep drawing stations 43.

What is claimed is:
 1. Tray for receiving liquid-secreting foodstuffsand delicacies, for example meat, fish or poultry, and having a basictray body having a length and a width and consisting of liquid-tightplastic and an absorbent insert, characterised in that the basic bodyconsists of two layers (11, 12) of liquid-tight plastic between which is.[.embedded.]. .Iadd.disposed.Iaddend., centrally relative to alongitudinal plane between the layers, a liquid-absorbent insert (13),in that the upper layer (11) pointing towards the foodstuff has orifices(14), in that the insert (13) is strip-shaped with a smaller width thansaid two layers and extends over only a limited region of the tray, sothat outside the region of the insert (13) the two layers (11, 12) arein direct contact with one another, in that said basic body has a bottomwall (44), in that the insert extends over the entire length of the twolayers (11, 12), and in that the width of the insert (13) correspondsapproximately to the width dimension of the bottom wall (44).
 2. Trayaccording to claim 1, characterised in that the upper layer (11) and thelower layer (12) form, outside the region of the insert (13), twolongitudinal side walls (15) projecting upwards from the bottom wall andwhich are directly joined to one another to hold the insert (13) looselybetween the layers (11, 12).
 3. Tray according to claim 2, characterisedin that the orifices (14) are continuous holes in the upper layer (11),and are grouped in two parallel longitudinal rows overlying the insert(13) and extending into two opposite transverse side walls (16) whichproject upwardly from the bottom wall (44) and which extend transverslyrelative to the longitudinal side walls (15).
 4. Tray according toclaims 1, 2 or 3 wherein said liquid-tight plastic is a foam materialselected from the group consisting of extruded polystyrene and expandedpolystyrene. .Iadd.5. Tray according to claim 1, wherein saidliquid-absorbent insert (13) is embedded between the two layers (11,12). .Iaddend.